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How to Choose the Right Outex Front Glass Port for Your Lens
Outex front glass ports match your lens filter thread diameter size — the same measurement as your lens cap, printed on the lens or cap with the symbol ⌀ (e.g. ⌀77). This is not your focal length. The port threads onto your lens just like a UV filter, moving with the lens for optimal optical positioning. Outex supports all standard sizes from 49mm to 105mm. For lenses without filter threads, dome ports are required.
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